Effects of central administration of alanine on body temperature of the rabbit: comparisons with the effects of serine, glycine and taurine.
Alanine, an amino acid that shares neural inhibitory effects with serine, glycine and taurine, like these three amino acids also lowers body temperature when given centrally. In the present experiments the effects of alanine on central temperature controls were examined in more detail to determine the relations between its central action and those of the other amino acids. Intracerebroventricular (ICV) injections of alanine (0.5--2.0 micrograms) caused small decreases in body temperature in a 23 degrees C environment, and greater decreases in a 10 degrees C environment. The 2.0 microgram dose had no effect at high temperature (30 degrees C). These results indicate that alanine shares the hypothermogenic activity of the other inhibitory amino acids. In common with these amino acids, alanine (2.0 microgram) also reduced LP fever and PGE2 hyperthermia. The hypothermogenic effect of alanine in 10 degrees C environment was additive with that of glycine but slightly subadditive with that of serine and of taurine. In previous experiments serine was additive with taurine and subadditive with glycine in lowering body temperature in the cold. The combined results indicate that alanine has an influence on central temperature controls that is comparable to those of glycine and taurine. Alanine, glycine, serine and taurine appear to act on similar receptors in the central thermoregulatory pathway, with serine and taurine possibly acting at additional receptor sites as well.
D000409:Alanine / Q000494:pharmacology*; D000818:Animals; D001427:Bacterial Toxins / Q000494:pharmacology; D001833:Body Temperature Regulation / Q000187:drug effects*; D004731:Endotoxins; D004768:Enterotoxins / Q000494:pharmacology; D005998:Glycine / Q000494:pharmacology*; D007276:Injections, Intraventricular; D007375:Interleukin-1; D008297:Male; D011458:Prostaglandins E / Q000494:pharmacology; D011506:Proteins / Q000494:pharmacology; D011817:Rabbits; D012694:Serine / Q000494:pharmacology*; D013654:Taurine / Q000494:pharmacology*
D001427:Bacterial Toxins; D004731:Endotoxins; D004768:Enterotoxins; D007375:Interleukin-1; D011458:Prostaglandins E; D011506:Proteins; C008270:leukocyte endogenous mediator; C027952:salmonella toxin; D013654:Taurine; D012694:Serine; D000409:Alanine; D005998:Glycine